Pinching seal for airtight containers

ABSTRACT

A cosmetic product container includes a dish and a cover, the dish having a base and a lateral wall, and the cover being equipped with a seal typically placed at the periphery of the cover. The seal includes at least one substantially axial internal lip and one substantially axial external lip that surround a recess intended to receive the upper edge of the lateral wall of the dish, the seal being designed so that when the upper edge of the lateral wall of the dish comes into contact with the base of the recess by transmitting an axial closing force (F) on the seal, the ends of the internal and external lips are subjected respectively to a centrifugal (E) and centripetal (I) lateral movement so that both come into contact with the lateral wall of the dish. The container may be a refill or a pan for a make-up compact.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to French Application No. 0510363 filed Oct. 11, 2005.

FIELD OF THE INVENTION

The invention relates to the field of containers for cosmetic products, typically compacts for make-up products, comprising a base and a cover, the cover and the base being provided with complementary closure means. It relates more specifically to compacts with a tight seal.

BACKGROUND

Cosmetic products, in particular for make-up and skin care, often contain volatile compounds that ensure some moisture upon application but that evaporate very quickly when in contact with the free air to leave a dry material on the skin. Other products, packaged similarly, may also contain compounds that are sensitive to air. All of these products must be packaged in airtight compacts in order to prevent their condition from quickly deteriorating and becoming either aesthetically unacceptable (for example, a dried-out product at the base of the compact pan) or unusable.

In general, the compacts include a hollow cover, typically equipped with an interior mirror, and a hollow base, typically equipped with a frame or intermediate support for one or more pans intended to receive the cosmetic product. The pans can be replaced with refills, enabling the user to pay only for the replacement of the product used while continuing to use the same compact. A refill is generally in the form of a dish or pan containing the cosmetic product, which may be in the form of a gel, foam, a cream, or, more generally, compacted or non-compacted powder. The so-called “airtight” compacts, normally used for these products, contain refills developed to provide a seal impervious to the air around the product. These refills are often “sleeved”, i.e. surrounded by a generally thermoformed and/or heat-shrunk sleeve or covered with a generally heat-sealed lid, after packaging so as to ensure proper preservation of the product until the first use by the consumer.

To achieve air-tightness, most make-up products comprising volatile components have usually been packaged in cylindrical containers with a circular, elliptical or oval orthogonal cross-section, such as a lipstick tube. With this type of container, it is easy to provide a good seal by diametrical interference between the cap and the body, i.e. by wedging a cylindrical lateral wall of the cap around a cylindrical wall of the body, with the diameter of the cylindrical wall of the cap at rest being slightly smaller than the diameter of the cylindrical wall of the body at rest. Some compacts use the same diametrical interference sealing system as lipstick tubes, but due to the large diameters of the pans, the diametrical interference necessary for ensuring air-tightness is often very high, thereby necessitating significant forces to close and open the compact. In addition, the parts associated with the tight seal must necessarily have a shape similar to a circle, an ellipse with low eccentricity or an unflattened oval so as to ensure good conformity of the diametrical, or lateral, interference over the entire periphery of the sealed area.

However, the diametrical or lateral interference, which allows for a tight seal, requires not only a relatively significant force to close the container (achieved by pressure on the cover), but also a high force to open it. This can be inconvenient for the user, because the application of such a force can result in a sudden opening of the compact with a risk of spilling the elements contained inside the compact.

The invention is intended to provide a compact for volatile components that does not have the aforementioned disadvantages and that allows for the application of a uniform pressure of the seal over the entire working surface thereof, regardless of the shape of the pan used and without requiring an excessive force to open and close the compact.

SUMMARY OF THE INVENTION

An object, according to aspects of the invention, is to provide a container for a cosmetic product including a dish and a cover, the dish having a base and a lateral wall, the cover being equipped with a seal typically placed at the periphery of the cover, wherein the seal includes at least one substantially axial internal lip and one substantially axial external lip that surround a recess intended to receive the upper edge of the side wall of the dish. The seal may be designed so that when the upper edge of the lateral wall of the dish comes into contact with the base of the recess by transmitting an axial closing force on the seal, the ends of the internal and external lips are subject, respectively, to a centrifugal and centripetal lateral movement so that both lips come into contact with the lateral wall of the dish.

To ensure air-tightness, it is necessary to have sealing means over the entire perimeter of the junction between the dish and the cover. This is why the seal may advantageously have the form of a closed contour, typically located at the periphery of the cover to benefit from the flexibility of the latter. The seal, according to aspects of the invention, includes an internal lip and an external lip that are substantially axial, i.e. oriented substantially in the direction of the application of the closing force, which itself is generally perpendicular to the base of the dish. The seal preferably has an even cross-section over its entire length and follows a closed contour of which the shape at rest corresponds to the general shape of the upper edge of the lateral wall of the dish. As the lateral wall is generally planar, the substantially axial internal and external lips are oriented in a direction substantially perpendicular to the plane of the seal.

The lips have significant height with respect to the thickness of the upper edge of the lateral wall of the dish. They surround a recess of which the width is slightly greater than the thickness of the upper edge of the lateral wall of the dish and of which the height is typically at least equal to half of the thickness. The seal according to embodiments of the invention is designed so that when the base of the recess is subjected to an axial compression stress, the ends of the internal and external lips are subjected, respectively, to a centrifugal and centripetal lateral movement so that they create a sort of macro-pinching of the upper edge of the lateral wall of the dish with two contact areas preventing air from entering. The adjectives “centripetal” and “centrifugal” are used here in a general sense, going beyond a purely axisymmetrical geometric configuration and also respectively mean “inward” and “outward”.

The internal and external lips preferably have a comparable flexibility and the movement of their ends has substantially the same amplitude. However, in particular for small containers, the external lip, which can be less flexible than the internal lip, may have an end that, without application of the closing force, is already near the lateral wall, and the pinching occurs essentially as a result of the centrifugal movement of the end of the internal lip.

Embodiments of the invention overcome the problems of dimensional tolerance in production associated with the desired diametrical or lateral interference. Aspects of the invention also overcome, with the pressure stress exerted horizontally on the seal being transformed into a lateral stress acting on the ends of the seal, the problems of planarity encountered in the compacts of the prior art. Indeed, even if the upper edge of the lateral wall does not come into contact with the base of the recess, the overall deformation of the seal may cause a pinching that provides, also in this location, two airtight areas. Embodiments of the invention also make it possible to instantaneously eliminate any diametrical interference upon unlocking of the compact, which in fact makes it possible to apply a lower opening force.

The examples provided below describe various seal cross-sections enabling the desired effect to be obtained. These seals are adapted to various embodiments and various possible applications. Their cross-sections are based on the same principle: the base of the recess can easily be bowed under the effect of axial stress, and its axial movement causes a bend in the seal resulting in a pinching of the internal and external lips. The profile of the cross section of the seal and that of the end of the edge of the lateral wall can be developed so as to find the best contact conditions according to the position of the desired contact area. For example, the presence of gadroons on the portions opposite the ends of the lips, at the end of the recess edge can allow for a greater contact surface under the direct effect of the axial closing force.

The cosmetic product container according to aspects of the invention may be a make-up product refill and/or a compact pan. As a refill, this container is preferably equipped with an overpack that maintains pressure on the cover. As a pan, the dish may be placed in the base of the compact, with the cover placed so that it is subjected to an axial closing force by means of either the main cover of the compact or by a secondary cover via axial interference.

The dish is preferably made of a material that acts as a barrier to the diffusion of the volatile product concerned. For example, if it is water, the dish will preferably be made of polypropylene; if it is silicone (for example, cyclomethicone), the dish will preferably be made of polypropylene (PP) or acrylic butadiene styrene (ABS); and if it is isododecane, the dish will preferably be made of polystyrene acrylonitrile (SAN).

The seal is made of a flexible material suitable for the volatile compound, for example, an elastomeric polymer such as a stryene-ethylene-butadiene-styrene (SEBS) copolymer or a silicone, preferably a bicomponent polymer, including two components that react when combined.

The cover can be made of any material if the seal covers it completely. Otherwise a material similar to that of the dish may be used, preferably a bit more rigid to preserve the shape of the cover, and therefore that of the seal, under the effect of the stresses caused when the container is opened and closed.

The invention also relates to a compact intended for packaging a cosmetic product for facial care, typically in the form of a gel, a pressed or unpressed powder, foam or a cream, the product including a product that is volatile or sensitive to air, the compact including a cover generally equipped with an interior mirror and a base equipped with an intermediate support for at least one pan intended to receive the cosmetic product, wherein the pan is a container such as that defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows an exemplary front view cross-section diagram of a container according to the invention with a first type of seal, before application of the closing force.

FIG. 1 b shows a front view cross-section diagram of the same exemplary container during application of the closing force.

FIG. 2 shows a front view cross-section diagram of a similar exemplary container with an alternative of the same type of seal, before application of the closing force.

FIGS. 3 a and 3 b show, respectively, before and during the application of the closing force, the front cross-sections of a second type of seal and the upper edge of the lateral wall of an exemplary container.

FIG. 4 shows, during the application of the closing force, a front cross-section diagram of a third type of seal overlapping the upper edge of the lateral wall of an exemplary container.

FIG. 5 shows, during the application of the closing force, a front cross-section diagram of a fourth type of seal overlapping the upper edge of the lateral wall of an exemplary container.

FIGS. 6 a and 6 b show, respectively, before and during the application of the closing force, the front cross-section diagrams of a fifth type of seal and the upper edge of the lateral wall of an exemplary container.

FIGS. 7 a and 7 b show, respectively, before and during the application of the closing force, the front cross-section diagrams of a sixth type of seal and the upper edge of the lateral wall of an exemplary container.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION Example 1 (FIGS. 1 a and 1 b)

The container 1 of this example is a refill for a cosmetic product including a dish 20 and a cover 10. The dish has a base 21 and a lateral wall 22. The cover 10 is equipped with a seal 30 that forms a closed contour at the periphery of the cover.

The seal 30 includes a substantially axial internal lip 31 and a substantially axial external lip 32 that together surround a recess 33 intended to receive the upper edge 23 of the lateral wall 22 of the dish 20. The seal 30 is designed so that when the upper edge 23 of the lateral wall 22 of the dish comes into contact with the base 330 of the recess 33 by transmitting axial closing force F on the seal, the ends of the internal 310 lips and external 320 lips are subjected, respectively, to a centrifugal (E) and centripetal (I) lateral movement so that both come into contact with the lateral wall 22 of the dish 20.

The seal 30 is made of a material suitable for the type of cosmetic product packaged. It must, in particular, have good barrier properties with respect to the volatile component that it contains. Depending on the material used, the seal can be made of an extruded or injected elastomeric thermoplastic, an injected and baked elastomer, or silicone, preferably injected as a bicomponent.

Once placed on the cover, the seal 30 typically follows a planar peripheral closed contour. The internal lip 31 and the external lip 32 are substantially axial, i.e. oriented substantially in the direction of application of the closing force, perpendicular to the base 21 of the dish and the plane of the seal. The recess 33 has a width that is slightly greater than the thickness of the upper edge 23 of the lateral wall 22 of the dish and of which the height of the recess 33, in this case, is on the order of twice the thickness. When the base 330 of the recess 33 is subjected to an axial compression stress F, the ends of the internal 310 lips and external 320 lips perform a sort of macro-pinching of the upper edge 23 of the lateral wall 22 of the dish 20 with several contact areas (in some embodiments, three areas) preventing air from entering. If there is a lack of planarity, such as when contact is not established in 43 between the upper edge 23 and the base of the recess 33, in an embodiment at least two contact areas 41 and 42 prevent air from entering.

The internal and external lips can have a comparable flexibility and the movement of their ends can have substantially the same amplitude.

Example 2 (FIG. 2)

The container of this example is a refill for a cosmetic product similar to that presented in the previous example, except that the seal is in the form of a molded elastomeric part that includes, in addition to the internal lips 31 and external lips 32, a central portion 34, and therefore entirely covers the cover 10. The cover 10 may, in this case, be made of any material, since the air-diffusion barrier is provided entirely by the seal and the dish, which must therefore be made of a material creating a suitable diffusion barrier.

Example 3 (FIGS. 3 a and 3 b)

The cover of the container of this example has a seal of which the cross-section has a low average thickness with respect to the height of the substantially axial lips, in this case typically less than one-fifth of the height. The ends of the internal and external lips have, on their opposing surfaces, gadroons 310′ and 320′, of which the smaller radius of curvature makes it possible to more precisely localize the contact areas 41′, 42′, to reduce the contact surface and to locally increase the normal stress in these areas. If, due to a lack of planarity, the contact is not established in 43′, there are at least two airtight contact areas in 41′ and 42′.

Example 4 (FIG. 4)

The container of this example may be small. Its cover has a seal of which the cross-section has an H-shape, with one of the notches of the H serving as a recess for receiving the upper edge of the lateral wall of the dish. The horizontal bar of the H, corresponding to the base 530 of the recess, is the thinnest portion of the cross-section of the seal and is easily bowed under the effect of a vertical force, causing the opening of the H branches above the bar and the closing of the H branches below it.

Example 5 (FIG. 5)

The container of this example also may be small. Its cover has a seal of which the cross-section is like that of the previous example, in the shape of an H, but it is non-symmetrical: the external lip, generally thicker and less flexible than the internal lip, has one end that, without application of the closing force, is already near the lateral wall and almost in contact therewith. The pinching is achieved essentially by the centrifugal movement of the end of the internal lip 52.

Example 6 (FIGS. 6 a and 6 b)

The cover of the container of this example has a seal made of an extruded thermoplastic elastomer, of which the cross-section has an open recess 63 that is intended to surround, then pinch the upper edge of the lateral wall of the dish, and a hollow interior 65 near the base of the recess 63, enabling the latter to be easily bowed. In this case again, when the closing force is exerted, the axial movement of the base of the recess causes a bend in the seal, which results in a rotation of the internal and external lips and, consequently, a centrifugal lateral movement of the end of the internal lip and a centripetal lateral movement of the end of the external lip.

Example 7 (FIGS. 7 a and 7 b)

The cover of the container of this example has a seal 70 of which the cross-section has a substantially constant thickness, which is low with respect to the height of the substantially axial lips, typically less than one-fifth of the height. In this way, the base of the recess can be bowed under the effect of the closing force by conforming to the shape of the upper edge 73 of the lateral wall of the dish. In this example, the upper edge 73 has a rounded shape, which increases the contact surface perpendicular to the closing force. 

1. A container for a cosmetic product comprising: a dish, the dish having a base and a lateral wall; and a cover including a seal disposed generally at the periphery of the cover, the seal comprising: at least one substantially axial internal lip having an end; at least one substantially axial external lip having an end; and a recess disposed between the internal and external lips, the recess having a base and configured to receive an upper edge of the lateral wall of the dish when an axial closing force is transmitted onto the seal and the upper edge of the lateral wall of the dish comes into contact with the base of the recess, subjecting the ends of the internal and external lips, respectively, to a centrifugal and centripetal lateral movement.
 2. The container according to claim 1, wherein the seal follows a closed contour of which the shape at rest corresponds to the general shape of the upper edge of the lateral wall of the dish.
 3. The container according to claim 1, wherein the recess has a width slightly greater than the thickness of the upper edge of the lateral wall of the dish and a height at least equal to half of the thickness of the upper edge of the lateral wall of the dish.
 4. The container according to claim 1, wherein the internal and external lips have a comparable flexibility so that the centripetal and centrifugal lateral movements of their ends resulting from the application of the closing force have substantially the same amplitude.
 5. The container according to claim 1, wherein the external lip is less flexible than the internal lip and the external lip comprises an end that, without the application of the closing force, is already located near the lateral wall of the dish, and the closing force on the seal causes substantially greater centrifugal movement of the end of the internal lip than centripetal movement of the end of the external lip.
 6. The container according to claim 1, wherein the base of the recess can easily be bowed under the effect of the axial closing force so that the axial movement of the axial closing force causes a bend in the seal resulting in a pinching of the internal and external lips on the upper edge of the lateral wall and creating at least two airtight contact areas.
 7. The container according to claim 1, wherein the ends of the lips comprise gadroons on their opposing surfaces, the smaller radius of curvature of the gadroons providing more precise localizations of the areas of contact with the lateral wall of the dish.
 8. The container according to claim 1, wherein the cross-section of the seal has a thickness smaller than one-fifth of the height of the substantially axial lips, and the upper edge of the lateral wall of the dish has a rounded shape.
 9. The container according to claim 1, wherein the dish is made of a material that acts as a diffusion barrier to a volatile product contained in the cosmetic product thus packaged.
 10. The container according to claim 1, wherein the seal further comprises a central portion, and the seal completely covers the cover and is made of a material that acts as a diffusion barrier to a volatile product contained in the cosmetic product thus packaged.
 11. A compact intended for packaging a cosmetic product for facial care that includes a compound that is volatile or sensitive to air, the compact comprising: a cover; a base equipped with an intermediate support for at least one pan configured to receive the cosmetic product; the pan comprising: a dish with a base and a lateral wall; and a cover including a seal comprising at least two substantially axial lips with a recess disposed between the lips such that an axial closing force applied to the cover causes an upper edge of the lateral wall to be received in the recess, creating at least two airtight contact areas between the lips and the lateral wall.
 12. The container according to claim 11, wherein the seal follows a closed contour of which the shape at rest corresponds to the general shape of the upper edge of the lateral wall of the dish.
 13. The compact according to claim 12, wherein the form of the product is chosen from the group consisting of a gel, pressed powder, unpressed powder, foam, and a cream.
 14. The compact according to claim 13, wherein the axial lips comprise ends and the airtight contact areas are achieved when the axial closing force causes the ends of the lips to be subjected to lateral movement to come into contact with the lateral wall.
 15. The container according to claim 11, wherein the end of at least one of the lips comprises a gadroon.
 16. The container according to claim 13, wherein the seal further comprises a central portion, and the seal completely covers the cover and is made of a material that acts as a diffusion barrier to the product contained in the cosmetic product thus packaged.
 17. A container comprising: a dish, the dish having a base and a lateral wall; and a cover including a seal disposed substantially at the periphery of the cover, the seal comprising at least one generally axial internal lip and at least one generally axial external lip each having an end, and defining a recess between the lips, the recess configured to receive an upper edge of the lateral wall of the dish and configured to bow at a base portion when an axial closing force is transmitted onto the seal to provide at least two airtight contact areas between the seal and the lateral wall of the base.
 18. The container according to claim 17, wherein a cross-section of the seal comprises an H-shape, including: a. an upper notch of the H-shape; b. a lower notch of the H-shape; and c. a horizontal bar of the H-shape, wherein the lower notch is configured to receive the upper edge of the lateral wall of the dish and the horizontal bar of the H-shape is configured to bow when the seal receives the upper edge of the lateral wall of the dish, the bowing causing the opening of the upper notch and the closing of the lower notch.
 19. The container according to claim 17, wherein a cross-section of the seal includes a hollow interior section near the recess, which may deform when the seal recess receives the upper edge of the lateral wall of the dish.
 20. The container according to claim 17, wherein the seal comprises an even cross-section over its entire length. 